This research evaluates SMSA characteristics as independent variables in explaining the selective migration processes which contribute to city-suburban population redistribution. Drawing from a theory of migration which views individual movement as a response, in part, to "pushes" and "pulls" associated with areas of move origin and prospective destination, this investigation focuses on physical, social, and economic characteristics of large SMSAs in order to explain the sizes and compositions of various migration streams. In addition, it provides a framework which will enable demographers to make projections of future migration and population redistribution within different types of SMSAs. The study utilizes published data from the 1960 and 1970 censuses as well as special tabulation from the 1970 census.